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Komga on Cloud Run — Lab Guide

📖 Configuration Guide

Overview​

Estimated time: 45–60 minutes

Komga is an open-source, self-hosted comics/manga reading server with a clean web UI, OPDS feeds, collections, read lists, and full-text search. This lab takes you through the full operational lifecycle of the Komga on Cloud Run module on Google Cloud: deploy it, access and verify it, run it day-to-day, observe it, diagnose common problems, and tear it down.

The lab focuses on operating the Cloud Run module and the Google Cloud platform, not on Komga product features. For the complete list of provisioned services and every configuration input (organised by group), see the Configuration Guide — this lab deliberately does not duplicate that detail so it stays accurate over time.

Objectives​

By the end of this lab you will be able to:

  • Deploy the module from the RAD platform and locate the resources it provisions.
  • Access and verify the running service.
  • Perform day-2 operations — inspect, update, and manage the persistent storage.
  • Observe the service with Cloud Logging and Cloud Monitoring.
  • Diagnose and resolve the most common deployment and runtime issues.
  • Tear the deployment down cleanly.

Prerequisites​

  • Services_GCP deployed in the target project (provides the VPC, Artifact Registry, and shared service accounts this module depends on).
  • A Google Cloud project with billing enabled.
  • gcloud CLI authenticated: gcloud auth login and gcloud auth application-default login.
  • Project Owner (or equivalent) IAM on the project.
  • RAD platform access with permission to deploy modules into the project.

Set these shell variables once; every task below reuses them:

export PROJECT="<your-gcp-project-id>"
export REGION="us-central1"          # the region you deploy into

Task 1 — Deploy the module [Automated]​

  1. In the RAD platform, open Komga (Cloud Run), set project_id, and review the inputs. Configure only what you need — the Configuration Guide documents every input by group, with defaults. Review the estimated cost (if credits are enabled) and click Deploy, which opens the deployment status page with real-time logs.

  2. The platform provisions the Cloud Run service, a Cloud Storage bucket mounted at /config via GCS FUSE, and deploys the official gotson/komga image directly (no build step, just an optional Artifact Registry mirror). There is no database to provision and no init job to run, so first deploys are fast — roughly 3–6 minutes.

  3. When it completes, discover the resources with name-agnostic filters (so the commands keep working regardless of the deployment suffix):

    SERVICE=$(gcloud run services list --project="$PROJECT" --region="$REGION" \
      --filter="metadata.name~komga" --format="value(metadata.name)" --limit=1)
    SERVICE_URL=$(gcloud run services describe "$SERVICE" \
      --project="$PROJECT" --region="$REGION" --format="value(status.url)")
    echo "Service: $SERVICE"
    echo "URL:     $SERVICE_URL"

Task 2 — Access & verify [Manual]​

  1. Confirm the service is healthy. Komga exposes an unauthenticated Spring Boot Actuator health endpoint:

    curl -s "$SERVICE_URL/actuator/health"   # expect {"status":"UP"}

    Note: $SERVICE_URL/api/v1/actuator/health is a different, auth-gated endpoint and returns 401 Unauthorized — this is expected and not a fault.

  2. Open $SERVICE_URL in a browser. On first visit Komga's setup wizard prompts you to create the initial administrator account — no pre-seeded admin credential exists in Secret Manager. After creating the admin account, add a library pointing at a mounted media path (see gcs_volumes in the Configuration Guide for adding a separate comics/books storage bucket) and trigger a scan.

Task 3 — Operate & keep it running (Day-2) [Manual]​

  1. Inspect the service and its revisions (each deploy creates an immutable revision; traffic shifts to the newest healthy one):

    gcloud run services describe "$SERVICE" --project="$PROJECT" --region="$REGION"
    gcloud run revisions list --service="$SERVICE" --project="$PROJECT" --region="$REGION"

  2. Scaling is intentionally fixed at 1. Komga serves one shared SQLite library from one mounted volume — do not raise max_instance_count above 1; multiple concurrent writers would risk corrupting the database.

  3. Update the application version tag by changing the application_version input in the RAD platform and applying it via Update — this deploys the corresponding gotson/komga tag directly (or its mirrored copy in Artifact Registry).

  4. Inspect storage:

    gcloud storage buckets list --project="$PROJECT" --filter="name~komga"

Task 4 — Observe: Logging & Monitoring [Manual]​

  1. Logs — from the CLI or the Logs Explorer:

    gcloud run services logs read "$SERVICE" --project="$PROJECT" --region="$REGION" --limit=50

    Logs Explorer filter: resource.type="cloud_run_revision" AND resource.labels.service_name="<service>".

  2. Monitoring — open the Cloud Run dashboard for the service and review request count, request latency (P50/P95/P99), instance count, and CPU / memory utilisation (JVM apps benefit from watching memory closely during large library scans). The module can provision an uptime check (when uptime_check_config.enabled = true — it defaults to false); if enabled, confirm it is green under Monitoring → Uptime checks.

Task 5 — Troubleshoot & debug [Manual]​

Durable techniques for the failure modes you are most likely to hit. These are platform-level diagnostics and do not change with Komga releases.

  • Revision unhealthy / service won't serve: inspect the latest revision and its logs for startup errors. The startup probe targets /actuator/health; confirm the probe path was not accidentally changed to the auth-gated /api/v1/actuator/health (which always returns 401, regardless of app health). 
    gcloud run revisions list --service="$SERVICE" --project="$PROJECT" --region="$REGION"
    gcloud run services logs read "$SERVICE" --project="$PROJECT" --region="$REGION" --limit=100
  • Library state missing after a redeploy: confirm enable_gcs_storage_volume is still true and the storage bucket is correctly mounted at /config — if this mount is ever disabled with no replacement, all library state (including the SQLite database) is lost on the next cold start.
  • Slow or failing library scans: check for OOM in the logs — Komga's Lucene index and thumbnail cache are held in the JVM heap; raise memory_limit (and optionally jvm_heap_max) for very large libraries.
  • Image build failed: review Cloud Build history — Komga uses a prebuilt image, so a build failure here almost always means container_image_source was accidentally changed to "custom" with no Dockerfile present.
  • 403 / permission errors: verify the runtime service account's IAM roles.

See the Configuration Guide's Configuration Pitfalls section for setting-specific gotchas.

Task 6 — Tear down [Automated]​

On the Deployments page, open the deployment and click the Trash icon (Delete). Delete runs terraform destroy and is irreversible (the deployment record is retained for history). If a deployment is stuck and the RAD platform can no longer manage it (for example after manual changes that conflict with the Terraform state), use Purge instead — it removes the deployment from RAD's records without destroying the cloud resources (it makes RAD forget the project). This removes everything the module created — the Cloud Run service, Secret Manager entries (if any were added manually), the GCS storage bucket, and Artifact Registry images. Resources owned by Services_GCP (the VPC, Artifact Registry repository itself) are managed separately and are not removed here.

Summary​

TaskTypeOutcome
1 — DeployAutomatedModule provisions Cloud Run, a GCS storage bucket mounted at /config, and deploys the prebuilt image — no database, no init job
2 — Access & verifyManualHealth check passes; create the initial admin account and add a library in the UI
3 — OperateManualInspect revisions, update version, inspect storage — scaling stays fixed at 1
4 — ObserveManualQuery Cloud Logging; review Cloud Monitoring metrics and uptime check
5 — TroubleshootManualDiagnose revision, storage-mount, memory, build, and IAM issues
6 — Tear downAutomatedDelete (Trash) removes all module resources

By · Google Cloud certified: ACE · PCA · PCD · PDE · PSE · CDL

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